Because modern science and technology are more and more based on mathematics, calculation skills have to be developed during education. This chapter discusses the methodological reasons behind many failures when students perform exercises, and proposes a structured method for helping them to succeed. It also proposes to analyze first why so many students have difficulties with calculations; knowing the errors is a way to avoid them in the future. The use of software for formal calculation is transforming science education, because calculations are much easier. The number of possible questions that arise from culinary processes is probably infinite, and the key point is to select the most useful ones, which can be solved using the simplest concepts and laws. When these simple laws are not enough, this shows the students why more studies are needed.